sinon

What is sinon?

Sinon is a testing utility that provides functions for spies, stubs, and mocks, which are essential for behavior-driven development and testing in JavaScript. It works with any unit testing framework and is widely used for its versatile API and comprehensive feature set.

What are sinon's main functionalities?

Spies

Spies are functions that record their usage, such as how many times they were called, with what arguments, and what was returned. They can be used to wrap existing functions to add this tracking ability.

const sinon = require('sinon');
const myFunction = sinon.spy();
myFunction('Hello', 'World');
console.log(myFunction.calledOnce); // true

Stubs

Stubs are like spies, but they can replace the target function's behavior, either by returning a specific value or by throwing an exception. They are useful for controlling a function's behavior in a test.

const sinon = require('sinon');
const myObj = { myMethod: () => 'original' };
const stub = sinon.stub(myObj, 'myMethod').returns('stubbed');
console.log(myObj.myMethod()); // 'stubbed'

Mocks

Mocks are fake methods (like stubs) with pre-programmed behavior and expectations. They are used to assert that certain methods are called in certain ways.

const sinon = require('sinon');
const myObj = { myMethod: () => 'original' };
const mock = sinon.mock(myObj);
mock.expects('myMethod').once().returns('mocked');
console.log(myObj.myMethod()); // 'mocked'
mock.verify();

Other packages similar to sinon

jest

Jest is a complete testing framework that comes with spies, mocks, and stubs built-in. It is often compared to Sinon for its mocking capabilities, but Jest provides a more integrated experience with a test runner and assertion library included.

testdouble

Testdouble.js (npm package 'testdouble') is a minimalistic testing library that provides a similar API to Sinon for creating test doubles like stubs, mocks, and spies. It focuses on providing a more user-friendly experience with better error messages and simpler APIs.

chai-spies

Chai-spies is a plugin for the Chai assertion library that adds spy capabilities. While it doesn't offer as comprehensive a set of features as Sinon, it integrates well with Chai for developers who prefer that assertion style.

README

Sinon.JS

Standalone and test framework agnostic JavaScript test spies, stubs and mocks (pronounced "sigh-non", named after Sinon, the warrior).

Compatibility

For details on compatibility and browser support, please see COMPATIBILITY.md

Installation

via npm

$ npm install sinon

or via sinon's browser builds available for download on the homepage. There are also npm based CDNs one can use.

Usage

See the sinon project homepage for documentation on usage.

If you have questions that are not covered by the documentation, you can check out the sinon tag on Stack Overflow or drop by #sinon.js on irc.freenode.net:6667.

You can also search through the Sinon.JS mailing list archives.

Goals

• No global pollution
• Easy to use
• Require minimal “integration”
• Easy to embed seamlessly with any testing framework
• Easily fake any interface
• Ship with ready-to-use fakes for XMLHttpRequest, timers and more

Contribute?

See CONTRIBUTING.md for details on how you can contribute to Sinon.JS

Backers

Thank you to all our backers! 🙏 [Become a backer]

Sponsors

Become a sponsor and get your logo on our README on GitHub with a link to your site. [Become a sponsor]

Licence

Sinon.js was released under BSD-3

Changelog

15.2.0

• 66b0081e Use fake-timers v10.1.0 re-released as v10.3.0 (Carl-Erik Kopseng)

  Version 10.2.0 of fake-timers had an unexpected breaking change. We re-released 10.1.0 as 10.3.0 to force users into jumping over the deprecated version.

  v10.2.0 was re-released as v11.0.0 and will be part of the next Sinon major

• a79ccaeb Support callable instances (#2517) (bojavou)

  • Support callable instances
  • Clean prettier lint

  ---

  Co-authored-by: - <->

• d220c995 fix: bundling compatibility with webpack@5 (#2519) (Avi Vahl)

  • fix: bundling compatibility with webpack@5

  when using webpack v5 to bundle code that calls require('sinon') (cjs) , it would have defaulted to "exports->require" and fail with multiple node-api requirements (util, timers, etc.)

  this patch ensures that anyone who bundles sinon for browser gets the (browser-compatible) esm version.

  tested on both webpack v5 and v4. should be noted that v4 worked even without this patch, as it automatically injected polyfills. v5 no longer does so. with this PR, people using webpack@4 to bundle sinon at least see size improvement, as the polyfills are no longer required.

  • fix: revert change for package.json -> "browser"

  browserify doesn't seem to like esm. leave that entry point alone, and ensure "exports" -> "browser" (which webpack@5 uses) is esm.

Released by Carl-Erik Kopseng on 2023-06-20.